The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Renee J Grayer - One of the best experts on this subject based on the ideXlab platform.

  • external flavones in sweet basil ocimum Basilicum and related taxa
    Phytochemistry, 1996
    Co-Authors: Renee J Grayer, Sarah E Bryan, Nigel C Veitch, Fiona J Goldstone, Alan Paton, Eckhard Wollenweber
    Abstract:

    Abstract Sixteen accessions of Ocimum Basilicum L. belonging to different cultivars and varieties, and one accession each of O. x citriodorum Vis. and O. minimum L., were examined for their external leaf flavonoids. The O. Basilicum samples showed the presence of one or two major flavone aglycones, which were identified as salvigenin and nevadensin, and up to 10 minor ones: cirsileol, cirsilineol, eupatorin, apigenin, acacetin, genkwanin, apigenin 7,4′-dimethyl ether, cirsimaritin, ladenein and gardenin B. No trace was found of xanthomicrol, the only lipophilic flavone so far reported from O. Basilicum . There were appreciable differences amongst the accessions in total flavonoid concentration and in their nevadensin / salvigenin ratios, which, on the whole, were not correlated with morphological characters. The surface flavonoid profile of O. x citriodorum was very similar to those of the O. Basilicum plants studied, but that of O. minimum was significantly different. Only 4′-methyl ethers of apigenin derivatives were detected in the latter taxon, whereas apigenin and luteolin derivatives in which the 4′-hydroxyls are free were absent. Furthermore, the ratio of nevadensin / salvigenin was much higher in O. minimum than in O. Basilicum or O. x citriodorum . These differences support the treatment of O. minimum as a separate species rather than as a variety of O. Basilicum .

  • infraspecific taxonomy and essential oil chemotypes in sweet basil ocimum Basilicum
    Phytochemistry, 1996
    Co-Authors: Renee J Grayer, Sarah E Bryan, Fiona J Goldstone, Alan Paton, Geoffrey C Kite, E Putievsky
    Abstract:

    Essential oil compositions of fresh and freeze-dried leaves were determined for 16 accessions of Ocimum Basilicum belonging to different varieties to see whether they could be used as infraspecific taxonomic characters. One accession of O. x citriodorum was also studied. Some 30 monoterpenoids, sesquiterpenoids and phenylpropanoids were identified, the major components (more than 20% of the total essential oil composition in one or more accessions) being geranial and neral in O. x citriodorum, and linalool, methyl chavicol, eugenol, methyl eugenol and geraniol in O. Basilicum. Based on a combination of the latter compounds, five major essential oil profiles could be distinguished in the accessions studied for O. Basilicum. These profiles were largely the same for fresh and freeze-dried material of the same plant, although in the dried leaves, methyl chavicol and eugenol concentrations had generally declined in comparison to those of linalool. There appeared to be little correlation between essential oil patterns and varietal classification within O. Basilicum. In view of the chemical heterogeneity of O. Basilicum and its use as an essential oil-producing crop, culinary herb, medicinal plant and insect-controlling agent, in all of which chemicals play an important role, the infraspecific classification of this taxon should take chemical characters into consideration. A system for the classification of essential oil chemotypes in O. Basilicum is proposed.

E Putievsky - One of the best experts on this subject based on the ideXlab platform.

  • evaluation and identification of basil germ plasm for resistance to fusarium oxysporum f sp Basilicum
    Plant Disease, 1997
    Co-Authors: Reuven Reuveni, E Putievsky, Nativ Dudai, Wade H Elmer, Robert L Wick
    Abstract:

    ABSTRACT Growth chamber evaluation of several cultivars of basil and related herbs examined in the United States revealed that identical cultivars from different sources did not differ in their reactions to artificial inoculation with Fusarium oxysporum f. sp. Basilicum. Cultivars differed in susceptibility to the pathogen: “Spicy globe” miniature was the most susceptible, and lemon basil (Ocimum Basilicum var. citriodorum), Origanum majorana, and Thymus vulgaris were rated as not susceptible. Twenty isolates of F. oxysporum, originating from stems of diseased basil plants in Israel, were pathogenic on basil in growth chamber and greenhouse tests. Under artificial inoculation, 2 isolates of F. oxysporum f. sp. Basilicum from stems were pathogenic to basil but not to 9 species representing Lamiaceae, Cucurbitaceae, Solanaceae, and Compositae indicating the specificity of the pathogen to basil. These isolates were used for additional resistance tests. Ocimum Basilicum var. purpurascens (Exotic) and var. cit...

  • infraspecific taxonomy and essential oil chemotypes in sweet basil ocimum Basilicum
    Phytochemistry, 1996
    Co-Authors: Renee J Grayer, Sarah E Bryan, Fiona J Goldstone, Alan Paton, Geoffrey C Kite, E Putievsky
    Abstract:

    Essential oil compositions of fresh and freeze-dried leaves were determined for 16 accessions of Ocimum Basilicum belonging to different varieties to see whether they could be used as infraspecific taxonomic characters. One accession of O. x citriodorum was also studied. Some 30 monoterpenoids, sesquiterpenoids and phenylpropanoids were identified, the major components (more than 20% of the total essential oil composition in one or more accessions) being geranial and neral in O. x citriodorum, and linalool, methyl chavicol, eugenol, methyl eugenol and geraniol in O. Basilicum. Based on a combination of the latter compounds, five major essential oil profiles could be distinguished in the accessions studied for O. Basilicum. These profiles were largely the same for fresh and freeze-dried material of the same plant, although in the dried leaves, methyl chavicol and eugenol concentrations had generally declined in comparison to those of linalool. There appeared to be little correlation between essential oil patterns and varietal classification within O. Basilicum. In view of the chemical heterogeneity of O. Basilicum and its use as an essential oil-producing crop, culinary herb, medicinal plant and insect-controlling agent, in all of which chemicals play an important role, the infraspecific classification of this taxon should take chemical characters into consideration. A system for the classification of essential oil chemotypes in O. Basilicum is proposed.

Eckhard Wollenweber - One of the best experts on this subject based on the ideXlab platform.

  • external flavones in sweet basil ocimum Basilicum and related taxa
    Phytochemistry, 1996
    Co-Authors: Renee J Grayer, Sarah E Bryan, Nigel C Veitch, Fiona J Goldstone, Alan Paton, Eckhard Wollenweber
    Abstract:

    Abstract Sixteen accessions of Ocimum Basilicum L. belonging to different cultivars and varieties, and one accession each of O. x citriodorum Vis. and O. minimum L., were examined for their external leaf flavonoids. The O. Basilicum samples showed the presence of one or two major flavone aglycones, which were identified as salvigenin and nevadensin, and up to 10 minor ones: cirsileol, cirsilineol, eupatorin, apigenin, acacetin, genkwanin, apigenin 7,4′-dimethyl ether, cirsimaritin, ladenein and gardenin B. No trace was found of xanthomicrol, the only lipophilic flavone so far reported from O. Basilicum . There were appreciable differences amongst the accessions in total flavonoid concentration and in their nevadensin / salvigenin ratios, which, on the whole, were not correlated with morphological characters. The surface flavonoid profile of O. x citriodorum was very similar to those of the O. Basilicum plants studied, but that of O. minimum was significantly different. Only 4′-methyl ethers of apigenin derivatives were detected in the latter taxon, whereas apigenin and luteolin derivatives in which the 4′-hydroxyls are free were absent. Furthermore, the ratio of nevadensin / salvigenin was much higher in O. minimum than in O. Basilicum or O. x citriodorum . These differences support the treatment of O. minimum as a separate species rather than as a variety of O. Basilicum .

Arunachalam Ganesan Murugesan - One of the best experts on this subject based on the ideXlab platform.

  • Biological activity of selected Lamiaceae and Zingiberaceae plant essential oils against the dengue vector Aedes aegypti L. (Diptera: Culicidae)
    Parasitology Research, 2012
    Co-Authors: Kandaswamy Kalaivani, Sengottayan Senthil-nathan, Arunachalam Ganesan Murugesan
    Abstract:

    The larvicidal activity of hydrodistillate extracts from Mentha piperita L. Ocimum Basilicum L. Curcuma longa L. and Zingiber officinale L. were investigated against the dengue vector Aedes aegypti L. (Diptera: Culicidae).The results indicated that the mortality rates at 80, 100, 200 and 400 ppm of M. piperita, Z. officinale , C. longa and O. Basilicum concentrations were highest amongst all concentrations of the crude extracts tested against all the larval instars and pupae of A. aegy pti. Result of log probit analysis (at 95% confidence level) revealed that lethal concentration LC_50 and LC_90 values were 47.54 and 86.54 ppm for M. piperita , 40.5 and 85.53 ppm for Z. officinale , 115.6 and 193.3 ppm for C. longa and 148.5 and 325.7 ppm for O. Basilicum , respectively. All of the tested oils proved to have strong larvicidal activity (doses from 5 to 350 ppm) against A. aegypti fourth instars, with the most potent oil being M. piperita extract, followed by Z. officinale , C. longa and O. Basilicum . In general, early instars were more susceptible than the late instars and pupae. The results achieved suggest that, in addition to their medicinal activities, Lamiaceae and Zingiberaceae plant extracts may also serve as a natural larvicidal agent.

Sarah E Bryan - One of the best experts on this subject based on the ideXlab platform.

  • external flavones in sweet basil ocimum Basilicum and related taxa
    Phytochemistry, 1996
    Co-Authors: Renee J Grayer, Sarah E Bryan, Nigel C Veitch, Fiona J Goldstone, Alan Paton, Eckhard Wollenweber
    Abstract:

    Abstract Sixteen accessions of Ocimum Basilicum L. belonging to different cultivars and varieties, and one accession each of O. x citriodorum Vis. and O. minimum L., were examined for their external leaf flavonoids. The O. Basilicum samples showed the presence of one or two major flavone aglycones, which were identified as salvigenin and nevadensin, and up to 10 minor ones: cirsileol, cirsilineol, eupatorin, apigenin, acacetin, genkwanin, apigenin 7,4′-dimethyl ether, cirsimaritin, ladenein and gardenin B. No trace was found of xanthomicrol, the only lipophilic flavone so far reported from O. Basilicum . There were appreciable differences amongst the accessions in total flavonoid concentration and in their nevadensin / salvigenin ratios, which, on the whole, were not correlated with morphological characters. The surface flavonoid profile of O. x citriodorum was very similar to those of the O. Basilicum plants studied, but that of O. minimum was significantly different. Only 4′-methyl ethers of apigenin derivatives were detected in the latter taxon, whereas apigenin and luteolin derivatives in which the 4′-hydroxyls are free were absent. Furthermore, the ratio of nevadensin / salvigenin was much higher in O. minimum than in O. Basilicum or O. x citriodorum . These differences support the treatment of O. minimum as a separate species rather than as a variety of O. Basilicum .

  • infraspecific taxonomy and essential oil chemotypes in sweet basil ocimum Basilicum
    Phytochemistry, 1996
    Co-Authors: Renee J Grayer, Sarah E Bryan, Fiona J Goldstone, Alan Paton, Geoffrey C Kite, E Putievsky
    Abstract:

    Essential oil compositions of fresh and freeze-dried leaves were determined for 16 accessions of Ocimum Basilicum belonging to different varieties to see whether they could be used as infraspecific taxonomic characters. One accession of O. x citriodorum was also studied. Some 30 monoterpenoids, sesquiterpenoids and phenylpropanoids were identified, the major components (more than 20% of the total essential oil composition in one or more accessions) being geranial and neral in O. x citriodorum, and linalool, methyl chavicol, eugenol, methyl eugenol and geraniol in O. Basilicum. Based on a combination of the latter compounds, five major essential oil profiles could be distinguished in the accessions studied for O. Basilicum. These profiles were largely the same for fresh and freeze-dried material of the same plant, although in the dried leaves, methyl chavicol and eugenol concentrations had generally declined in comparison to those of linalool. There appeared to be little correlation between essential oil patterns and varietal classification within O. Basilicum. In view of the chemical heterogeneity of O. Basilicum and its use as an essential oil-producing crop, culinary herb, medicinal plant and insect-controlling agent, in all of which chemicals play an important role, the infraspecific classification of this taxon should take chemical characters into consideration. A system for the classification of essential oil chemotypes in O. Basilicum is proposed.